Have you tried making investigation to know the reason why most of this parents have choosen to send thier children to public school? Sometimes you have to think twice before jumping into conclusion, you don't necessarily need to blame them for enrolling thier children into public they may also have a reason for doing that which is best known to them so I will advice you stop making a big deal out of it. And if you're not comfortable with thier decision then you have every right to enroll them in a more decent school that you feel will be best for them I'm sure the parents is going to appreciate you for doing that .